(1)Z6(m)=∑8()xm=1 0 (2)ZT[S(n-m)]=28(n-m)z-n=z )Z7Gm+)=∑+1x+∑8 n+1)z n10 =x2+0=z  =  =   = − n n ( ) ZT[ (n)] (n)z z z ZT n n z n z n n n n = +  =   + =  + +  +   = − − =−  − ( ) [ ( )]  ( )  ( ) m n n ZT n m n m z z −  = − − =  − = 0 (2) [ ( )]  ( )